The fine structure of the testicular interstitial cells in men of normal androgenic status

Summary

The ultrastructural features of the testicular interstitial cells were examined in a group of men of normal androgenic status. In osmium-fixed material three cell types were identified, namely, an immature cell, a light cell, and a dark interstitial cell not previously described. The dark cells possessed increased amounts of tubular agranular endoplasmic reticulum, variable numbers of membrane-bounded bodies, and accumulations of glycogen granules. These differed from the light interstitial cells which possessed both tubular and vesicular forms of agranular endoplasmic reticulum, no demonstrable accumulation of glycogen, and in general the membranous components of the light cells were less electron dense than in the dark cell. Intermediate forms between the cell types were observed. Tubular crystalline inclusions with a regular substructure were described and a hypothesis linking these structures with the formation of the crystals of Reinke is discussed. A new cytoplasmic inclusion consisting of aggregations of short dense rod-shaped structures seen in these cells, was also described.